Spectrographic analysis for selected minor elements in Pierre shale

The Copper Canyon deposit, largest producer of copper in the Battle Mountain mining district, is about 19 km southwest of the town of Battle Mountain, in north-central Nevada. The district is at the north end of the Eureka-Battle Mountain mineral belt a northwest-southeast zone of metal-mining districts. Du~al Corp. has mined copper, gold, and silver from the Copper Canyon deposit by open-pit methods since 1967. The deposit formed in chemically favorable wallrock adjacent to a small potassic-altered granodiorite intrusion. The granodiorite was emplaced under about 1,500 m of cover into a complex thrust sequence of lower and upper Paleozoic rock in late Eocene or early Oligocene time (about 38 million years ago). Emplacement is inferred to have been controlled partly by the Virgin fault, a major north-striking normal fault in this part of the district, along which movements continued after crystallization of the intrusion. Experimentally determined minimum melting curves, together with univariant breakdown curves for primary biotites from this intrusive, suggest that biotite may have crystallized at about 800°C and suggest high PH 2 0: Ptotal equilibrium ratios during the crystallization. The deposit occurs predominantly as hypogene replacement sulfides in altered rocks belonging to the Middle Pennsylvanian Battle Formation. Smaller amounts of ore occur in the Upper Cambrian Harmony Formation and in the Pennsylvanian(?) Pumpernickel Formation. Most ore was deposited in beds that originally contained hematite and calcite. The hypogene minerals include pyrite, chalcopyrite, pyrrhotite, marcasite, arsenopyrite, sphalerite, molybdenite, galena, and gold. Gold is the second most economically important metal in the deposit. The most common gangue minerals are quartz, K-feldspar, biotite, and white mica, typical of the potassium silicate alteration facies. Early-stage sulfide deposition, beginning at temperatures of about 300°C and continuing to at least 360°C, may have occurred when metal-bearing :fluids reacted with hematite-rich beds of the Battle Formation. Oxygen fugacities in the environment of ore deposition appear to have been very low during this stage. Later, during the intermediate stages, siderite-and marcasite-bearing assemblages developed as the :fluide became enriched in C02 and became possibly more acidic because of the dissociati<* of hydrogen gas. Most gold may have been 1 Duval Corp., Battle Mountain, Nev. 89820. deposited very late in the metallization sequence, along with quartz that fills vugs. Ore deposits peripheral to the intrusion at Copper Canyon are zoned successively from copper-gold-silver deposits near the center to gold-silver to lead-zinc-silver deposits in the northernmost parts of the area. Over 2,900 rocks across all three zones were analyzed for 31 elements in an area of about 16 sq km, up to about 3.2 km north of the main intrusion at Copper Canyon. The chemical data indicate many very high local concentrations of metals near the lead-zinc-silver and the gold-silver peripheral vein d...

Section: Boronmentioning

confidence: 99%

Section: Chromiummentioning

confidence: 99%

Geology and geochemistry of the Copper Canyon porphyry copper deposit and surrounding area, Lander County, Nevada

Theodore¹,

Blake²

1975

“…The availability of a large number of similar samples on which much analytical work, chemical as well as spectroscopic, will have been done, gave P. R. Barnett (1961) an excellent opportunity to make a detailed study of the precision of the conventional d-c arc procedure for 10 minor elements as applied to shales. He determined from 80 samples the following values for the precision of a single determination (in terms of the coefficient of variation of a single determination): boron, 10 percent; barium, 11; cobalt, 7; chromium, 9; gallium, 20; nickel, 7; scandium, 10; strontium, 13; titanium, 6; and zirconium, 10 percent.…”

Section: Quantitative Spectrographic Analysis For Selected Minor Elements In Pierre Shalementioning

confidence: 99%

Geological Survey research 1962; synopsis of geologic, hydrologic, and topographic results

1962

The reception accorded the 1960 and 1961 Annual Reviews of Geological Survey research has encouraged us to prepare this volume, "Geological Survey ," in a continuing effort to publish more quickly the significant results of our current investigations. We continue to consider these reports as experimental and have again this year modified the content, format, and frequency of release of chapters in an attempt to serve better the interests of the users of the reports. The comments and suggestions of these users are here solicited and will be considered carefully as future volumes are planned.The current Annual Review consists of five chapters (Chapters A through E) of Professional Paper 450. As in the preceding two Annual Reviews, Chapter A is a synopsis of recent findings in the many and varied lines of study pursued by Survey personnel. Chapters, B, C, D, and E of this volume are collections of short articles in geology, hydrology, topography, and allied fields. These articles are numbered as follows: Prof. Paper 450-B Articles 1-59 Prof. Paper 450-C Articles 60-119 Prof. Paper 450-D Articles 120-179 Prof. Paper 450-E Articles 180-239 These four chapters have been released at about three-month intervals during the year (Chapter E is in preparation as this foreword is written) so that timely articles could reach the reader more quickly.Results of research presented in this chapter, Chapter A, are representative of our many projects; complete coverage of all projects would result in an unwieldy volume. A complete list of our publications during fiscal year 1962 can be found on pages A197 to A250 Readers interested in learning of our current work in certain geographic areas or on specific topics will find a complete listing of investigations in progress in the Geologic and Water Resources Divisions during fiscal year 1962 on pages A137 to A186. The status of mapping by the Topographic Division is included this year for the first time, on pages A187 to A195, Addresses of our main centers and field offices and names of officials in charge are presented on pages A128 to A132 for readers who wish to contact our personnel directly.During fiscal year 1962, the services of the Geological Survey were utilized by or were supported financially in part by, the numerous Federal, State, County and City agencies listed on pages A133 to A136. Some work reported in these chapters may be a direct result of cooperative investigations in previous years with agencies not shown on the current list. Cooperating agencies are acknowledged in the articles in Chapters B, C, D, and E, but space limitations preclude mention of individual cooperators in the summary statements in Chapter A. \ The current Annual Review represents the combined efforts of many individuals. Arthur B. Campbell assumed overall responsibility for the preparation of the report and assembled Chapter A from information supplied by many project chiefs and program leaders. He was assisted by Joshua I. Tracey, Jr., who critically reviewed the manuscripts for Chapters B, C, D...

“…From 1956 to 1968, a detailed regional study of the stratigraphy, paleontology, mineralogy, and geochemistry of the Pierre Shale and equivalent rocks in the northern part of the western interior was undertaken by various members of the U.S. Geological Survey (Tourtelot, 1956(Tourtelot, , 1962Tourtelot and others, 1960;Schultz, 1964Schultz, , 1965Scott andCobban, 1963, 1965;Barnett, 1961;Rader and Grimaldi, 1961;Kepferle, 1959;Landis, 1959;Gill and Cobban, 1961, 1962, 1965, 1966aRobinson and others, 1959). During this investigation, they studied type sections of members of the Pierre Shale along the Missouri River and in the Black Hills region in South Dakota as well as the equivalent rocks in North Dakota, Montana, Wyoming, and Colorado.…”

Section: Introductionmentioning

confidence: 99%

Stratigraphy and composition of the Sharon Springs Member of the Pierre Shale in western Kansas

Gill¹,

Cobban²,

Schultz³

1972

The Sharon Springs Member of the Pierre Shale is a widespread unit that can be recognized readily in outcrops by its distinctive lithologic character and in the subsurface by electric and gamma-ray well-log characteristics. The Sharon Springs Member is in Kansas, Nebraska, North and South Dakota, and parts of Colorado, Wyoming, Montana, and eastern Utah. Its type locality is in Wallace County, Kans., where the member is about 215 feet thick and consists of three units: a lower dark soft shale unit 115 feet thick, a middle hard organic-rich shale unit 90 feet thick, and an upper hard slightly phosphatic shale unit about 10 feet thick. The Sharon Springs contains abundant vertebrate remains but few mollusks. Minerals in the Sharon Springs Member, as determined from well cuttings, are predominantly clay minerals but include about 25 percent quartz and several percent each of pyrite, dolomite, organic matter, and, in the lower part where the member grades into the Niobrara Formation, calcite. The most abundant clay mineral is mixed-layered montmorilloniteillite; there are lesser amounts of illite, kaolinite, and chlorite. Pyrite, dolomite, and chlorite are leached from outcrops. Bentonite beds in the Sharon Springs contain unusually large amounts of kaolinite and beidellite with interlayered hydrated aluminum complexes in comparison with the usual montmorillonitic bentonites in other parts of the Pierre Shale. The rare mineral basaluminite occurs as white earthy lumps at the top of the Sharon Springs Member. Semiquantitative spectrographic data indicate that most trace elements occur in the clay component of the shale or in closely associated heavy clastic grains. Iron, nickel, cobalt, and molybdenum are concentrated in pyrite. Molybdenum and probably uranium and silver seem strongly concentrated in organic matter. Strontium is concentrated in calcite. HISTORICAL BACKGROUND Loc. Location 1Mohler (1889, map on page 278) showed McAllaster to be along the Union Pacific Railroad, just north of the center of sec. 23, T. 12 S., R. 37 W., and Sheridan to be along this railroad east of the North Fork of Smoky Hill River in about the W% sec. 8, T. 12 S., R. 36 W.